Esters of acylated lactic acid



Patented Apr. 1, 1952 UNITED "STATES PATENT OFFICE ESTERS F ACYLATED LACTIC ACID Martin L. Fein, Riverside, N. J., and Charles H.

Fisher, Abington, Pa., assignors to the United States of America as represented by the Secretary of Agriculture 11 Claims. (Cl. Milk-345) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0'. G. 757) This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described and claimed if patented in any country, may be manufactured and used by or for the Government of the United States of America throughout the world for governmental purposes without the payment to us of any royalty thereon.

This application is a continuation in part of our copending application Serial No. 588,882, filed April 1'7, 1945, now Patent No. 2,448,873.

This invention relates to compositions comprising esters of alpha-acyloxypropionic acids and has among its objects the provision of new compositions of matter and processes for their preparation. Another object of the invention is to provide plasticizing agents suitable for use with cellulose derivatives such as cellulose acetobutyrate or ethyl cellulose and also with polyvinyl resins such as coploymers of vinyl acetate and vinyl chloride.

We have found that esters of lactic acid can be converted to the corresponding esters of alphaacyloxypropionic acid by interaction with acyl halides of higher fatty acids. We have further found that the resulting products are compatible with ethyl cellulose and with copolymer of vinyl chloride and vinylacetate and are useful as modifying agents adapted to enhance the mechanical characteristics of these resins.

In accordance with this invention the ester of lactic acids is reacted with an acyl halide preferably in the presence of a solvent or diluent, and an organic base capable of combining with the hydrogen halide liberated in the reaction. The resulting ester of alpha-acyloxy propionic acid can be recovered from the reaction mixture by distillation. 3

Suitable esters of lactic acid include the esters =0f lactic acid with aromatic and aliphatic ether alcohols or with tetrahydrofurfuryl alcohol described in application Serial No. 588,882 and also alkyl estersof lactic acid. Suitable acyl halides are those of higher saturated fatty acids containing from seven to eighteen carbon atoms, like heptoylchloride, pelargonyl chloride, or lauroyl chloride. In producing the plastic compositions -;of this invention the synthetic resin and the modifying agent may be combined by dissolving them in a common solvent and allowing the solvent to evaporate, or by milling or by any other conventional technique. Fillers, dyes, extenders, pigments and other compounding ingredients may be included if desired.

: i The iollowing Examples I through IV describe z 7 I. the preparation of some suitable lactic acid esters. Others are described in application Serial No. 588,882.

I EXAMPLEI One mole of 81.8 percentlactic acid '(110 grams) in aqueous solution was refluxed with '75 ml. of benzene under a Vigreux column (200 mm. long) which supported a moisture trap (Barrett modification of the Dean and Stark tube). After about 20 cc. of water had been removed, 4 moles of beta-butoxyethanol (472 grams) and 1 cc. of concentrated HzSOr were added. After continuing the refluxing as de scribed above for about 10 hours, a total of 24 cc. of water was removed. When the flask had cooled 4 grams of anhydrous sodium acetate was added to neutralize the catalyst. The benzene present was distilled at about 30 mm. The excess alcohol was removed by distillation at 51 C. under a pressure of 4 mm. Butoxyethyl lactate was distilled at 107 to 108 C. at 4 mm.; N =1.4320. The yield was 154 grams or 81 percent of the theoretical.

EXAMPLE II Using the procedure described in the foregoing example chloroethoxyethyl lactate was prepared from one mole of lactic acid and four moles of beta-chloroethoxyethanol. The ester distilled at 111 C. under a pressure of 1.6 mm.; N =1.4568.

The yield was 79 percent of the theoretical.

EXAMPLE III EXAIWPLE IV Tetrahydrofurfuryl lactate was prepared by a procedure analogous to that described in Example I except that no catalyst was used and 4 moles of tetrahydrofurfuryl alcohol was added to the flask containing the lactic acid from which about 20 cc. of Water had been removed. During the 10 hours of refluxing 22 cc. of water was collected in the trap. Benzene was removed by distillation at atmospheric pressure. The excess alcohol was distilled at 56 to 59 C. (4 to 5 mm). The ester was collected at 1149-115" C. under a pressure of 5 mm.; N 1 ,45 55 The yield was 79 percent of the theoretical The following examples illustrate the preparation of the esters of this invention:

EXAMPLE V Lauroyl chloride (0.5 mole, 109.4 g.) was added slowly with constant stirring to a cooled mixture of beta-butoxyethyl lactate (0.5 mole, 95.1 g.), pyridine (50 g.) and benzene (100 ml.), while maintaining the reaction temperature below C. When the reaction was completed, a small amount of water was added to dissolve the pyridine hydrochloride formed. The benzene layer, containing the desired product, was separated and washed with aqueous solution of sodium chloride to remove free acidity. The neutral benzene.

layer was then dried over anhydrous sodium sulfate and the solvent distilled under reduced pressure. Beta-butoxyethyl ester of alpha-lauroyl oxy-propionic acid (beta-butoxyethyl lactate laurate) was distilled at approximately 203 C. under 3 mm. pressure; N :1.44l2.

Other esters of alpha-acyloxypropionic acid were prepared by the use of various reactants in accordance with the method described in Example V. The results obtained are given in the fol- I wherein R is a radical of the group consisting of butyl, tetrahydrofurfuryl, butoxyethyl, chloroethoxyethyl, and butoxyethoxyethyl, and R is the acyl radical of a fatty acid containing from 7 to 18 carbon atoms.

2. A compound defined as in claim 1 wherein R is heptoyl. I

3. A compound defined as in claim 1 wherein is pelargonyl.

4. A compound defined as in claim 1 wherein R is lauroyl.

5. A plasticizer and modifier for polyvinyl chloride-acetate resins being a compound 'corresponding to the general formula CAHQ-O"C O(IJHCH:;

wherein R. is the acyl radical of a saturated fatty acid containing from 7 to 18 carbon atoms.

lowing table: 6. A plasticizer and modifier for polyvinyl chlo- Table I Reactants igg A d Product B. 1. (approx) Np Lactate Chloride VI! -V beta-Butoxyethyl PclargonyL. heta-Butoxyethyl lac- 176C./5.5 mm 1.4370 tate pelargonatc. VII Tetrahydrolur- Lam-03d..- Tetrahydrofuriuryl lac- 205C./2.7 mm 1.4522

luryl. tate laurate.

Heptoyl. 'Ietrahydrofurfuryl lacl7lC./5.4 mm" 1.4478

tate heptoatc. do l. Butyl lactate heptoatc" 142C./6.6 mm- 1.4290 Louroyl Butyl lactate laurate.. 200C./0.8 mm 1.4388 Pelargonyl beta-Chloroethoxyethyl 162C./2.0 mm 1.4490 ethyl. lactate pelargonate. XII Totrahydroiurfuryl. do Tetrahydroiurluryl lac- 202C./l0 mm. 1.4498

tate pelargonate. XIII Butyl do Butil lactate pelargol43O./3.0 mm 1.4335

na e. XIV"... beta-Butoxycthoxydo. beta-Butoxyethoxy- 191C./4.5 mm 1.4402

ethyl. ethyl lactate polargonate.

All the products of Examples V-XIV are compatible with ethyl cellulose, cellulose acetate butyrate and polyvinyl resins (vinyl chloridevinyl acetate copolymers) but not with cellulose acetate.

The plastici'zing eificiency of these products was determined by compounding them with a polyvinyl chloride-acetate copolymer (95 vinyl chloride, 5% vinyl acetate) using a procedure analogous to that described by Kent and Weaver (1947, India Rubber World, 115, 813-816). The results of some of these tests are shown in the following table:

Having thus described our invention, we claim; 1. A plasticizer and modifier for polyvinylride-acetate resins being a compound corresponding to the general formula IMG 0115 112C UHCHQOC OClI- II::

wherein R is the acyl radical of a saturated fatty acid containing from 7 to 18 carbon atoms.

7. A plasticizer and modifier for polyvinyl chloride-acetate resins being a compound of the formula 8. A plasticizer and modifier for polyvinyl chloride-acetate resins being a compound of the formula 9. 'A plasticize'r' and modifier for polyvinyl chloride-acetate resins being a compound of the Hg([3-CH formula mo oH-cmo-c O-QH-JJH:

fizcwcm o (|3(CH2)1CH3 ml H-CHz-O-JJO-CH-CH; t

-C(CH2)5CH.1

, H MAR-TIN L. FEIN.

' CHARLES H. FISHER. 10. A plasticizer and modifier for polyvinyl chloride-acetate resins being tetrahydrofurfuryl 10 lactate la-urate, of the formula:

REFERENCES CITED The following references are of record in the file of this patent:

H CCH:

I L UNITED STATES PATENTS me LHCHz-O-C O-OH-CHa I 15 Number Name Date 0 f' 1,927,295 Powers Sept, 13, 1933 2,046,150 Cox et al June 30, 1936 7 2,122,716 Graves July 5, 1938 11. A plasticizer and modifier for polyvinyl ,2 ,3 labom NOV. 19, 1940 Wiley et :31. Feb. 25, 1941 chloride-acetate resins being tetrahydrofurfuryl 20 2,232,933

Guest et a1. June 3, 1947 lactate pelargonate, of the formula: 2,421,373 

1. A PLASTICIZER AND MODIFIER FOR POLYVINYLCHLORIDE-ACETATE RESINS BEING A COMPOUND CORRESPONDING TO THE GENERAL FORMULA: 